At one time, artisans specializing in manufacture of metal molds were well aware of the know-how of metal mold machining from the beginning to the end thereof, and contrived a means in conformity with components to be machined, to make inexpensive and high-quality metal molds.
However, by introduction of the NC machine and CAM technology, the work process was divided into NC data generation, NC machining, and finishing. The current CAM program assumes a uniform working method, and aims to enable anyone to machine the metal molds with simple operations by standardization of the working condition, datalization of the working pattern, and usage of the high-speed machine.
Therefore, it is assumed that a work to be machined has a specific shape and tools are new.
In such an environment, information communication between an NC data generation department and a machining department is carried out by using communication document forms, such as instruction sheets and/or working drawings, feedback document forms used when a machining failure occurred and the like. Incidentally, these document forms are paper sheets or electrical data.
As a result of unnoticed progress of the division of work and the partial optimization, a communication gap between persons in charge of the NC data generation and machining operators existed, and a wall against the improvement of technology and skill was formed.
JP-A-08-257874 discloses a technique in which outside dimension of a work piece is measured by a distance measuring device, and in a case where the outside dimension is smaller than machining dimension described in a NC machining program mentioned above, a machining start position is corrected so as to be adjacent to a side of the work piece in accordance with the dimensional difference.